We know that a major contributor to rising spam levels is botnets - networks of compromised computers. According to industry findings, however, only a handful of botnets were responsible for the majority of spam sent in February. Six botnets spewed out 85 percent of all spam last month, the first time so few botnets were found to be responsible for so much spam, a Marshal report says.

Interestingly, the Storm botnet, which is thought to be one of the largest known botnets, was responsible for only 2 percent of spam in February, according to the findings. One of the latest botnets making the news for spreading spam is known as Mega-D. Is this new botnet outpacing the Storm botnet? There's some speculation that Mega-D is actually a subset of Storm.

Want to learn more about recent spam trends? In the March issue of Lavasoft News, we focus on this plague of the Net.